Fuzzy-model-based H∞ control for discrete-time switched systems with quantized feedback and unreliable links

Stability analysis and stabilization of discrete-time switched Takagi-Sugeno fuzzy systems

We endeavor to investigate the H_∞ synthesis problem of switched fuzzy systems composed by several discrete-time subsystems. By designing a novel QTD-MD Lyapunov function, novel criteria assuring stability as well as an expected H_∞ performance are first developed. Based on these sufficient conditions, some other conditions for solving the fuzzy H_∞ controllers are derived subsequently. Furthermore, the criteria are given as LMIs, thus the implementations are easy to execute. Simulations are also provided to confirm the feasibility of the presented strategy.

Nonfragile H∞ control for periodic stochastic systems with probabilistic measurement

This paper addresses the problem of nonfragile H_∞ control for periodic stochastic systems with probabilistic measurement. A novel Lyapunov-Krasovskii functional is formulated, which makes full use of both delay and its change rate. In view of the measurement signal, the mode-dependent stochastic variables are employed and new sufficient conditions are achieved. Finally, two numerical examples are worked out to demonstrate the effectiveness of the proposed control design.

A Compound Controller Design for a Buck Converter

In order to improve the performance of the closed-loop Buck converter control system, a compound control scheme based on nonlinear disturbance observer (DO) and nonsingular terminal sliding mode (TSM) was developed to control the Buck converter. The control design includes two steps. First of all, without considering the dynamic and steady-state performances, a baseline terminal sliding mode controller was designed based on the average model of the Buck converter, such that the desired value of output voltage could be tracked. Secondly, a nonlinear DO was designed, which yields an estimated value as the feedforward term to compensate the lumped disturbance. The compound controller was composed of the terminal sliding mode controller as the state feedback and the estimated value as the feedforward term. Simulation analysis and experimental verifications showed that compared with the traditional proportional integral derivative (PID) and terminal sliding mode state feedback control, the proposed compound control method can provide faster convergence performance and higher voltage output quality for the closed-loop system of the Buck converter.